The Bitcoin Core PR review club site links to this beginner's guide to IRC.
There are more impressive IRC setups such as Pieter Wuille's setup.
But you said you wanted to minimize setup time. In that case I would recommend Textual on MacOS (as pinhead does in his answer). It isn't free, the license costs $7.99 at the time of writing (September 2020). There is a FAQ for using Textual here.
This will allow you to join the Bitcoin Core PR review club meetings but you won't be able to receive messages or view discussion that has happened on channels while you were offline. You would need to set up a bouncer on a virtual private server to do that (or refer to third party conversation logs). For that I recommend ZNC but first get set up with a IRC client like Textual.